Min Stack

MinStack.java

class MinStack {

    Stack<Integer> stk= new Stack<Integer>();
    Stack<Integer> min= new Stack<Integer>();
    
    public void push(int x) {
        if (min.empty()){
            min.push(x);
        }
        else{
            if (x <= min.peek()){
                 min.push(x);
            } 
        }
        stk.push(x);
    }

    public void pop() {
        if (stk.peek().equals( min.peek() )){
            min.pop();
           
        }
        stk.pop();
        
    }

    public int top() {
        return stk.peek();
    }

    public int getMin() {
        return min.peek();
    }
}